What makes an airgun scope?

by B.B. Pelletier

Riflescopes have changed significantly over the past 20 years, and airguns have lead the way. Things such as parallax adjustment, sidewheel parallax adjustment, and adjustable scope mounts have all come out of the demand for better scope solutions by airgunners. And, because of all these changes, what airgunners “know” about airgun scopes has also changed – perhaps too fast for most people to keep up.

Airguns no longer break scopes!
In the 1970s, scoping an airgun was problematic, because all the scopes then made were made for firearms. Scope breakage reared its ugly head about the time the great horsepower race began. Airgunners wanted guns that went at least 800 f.p.s. – the minimum speed for magnum status. To build guns that could do it, airgunsmiths created guns with more forward recoil and vibration than had been seen up to that time. Scopes started breaking. A .30-06 recoils more than nearly all airguns, but it kicks the rear – not to the front. So, scopes were braced for rearward recoil. A .375 H&H Magnum kicks pretty hard, but it doesn’t vibrate. A Diana 45 with a leather piston seal and sloppy internal tolerances can give you a headache from the high-speed vibration. That’s why the early scopes broke.

Scope makers didn’t advertise the fact, but in the 1980s and early ’90s they quietly cleaned up their act. It’s difficult to find a scope that’s not properly braced for an airgun today. A few cheapos from China are all that remain of this once-widespread malady. Scopes don’t break – as a rule. That said, airguns are still hard on scopes, and individual scopes will still break. I hope you understand the difference.

Parallax adjustment
In scope manufacturing companies where there are real optical engineers, the subject of parallax adjustment is understood very well. Leupold was at the front of the pack in the early 1990s with Premier Reticle, an independent customizing house that specializes in Leupold modifications, leading the way. I can remember being shocked to learn that Premier Reticle could bring the adjustable parallax of a 6.5-20x scope down to as close as 10 yards. Today, Leupold offers the scope that way off the shelf, but so does nearly everyone else.

However, you should be aware that some companies that don’t actually produce the scopes they sell. With today’s world market, it’s possible for anyone to become a manufacturer by aligning with the right Chinese company and getting them to put your name on some scopes. When two guys in a garage decide to make riflescopes and they haven’t got a clue what parallax adjustment really is, you’ll see goofball minimum distances like 20 or 25 yards. All that does is signal a company that hasn’t got anyone on their staff who understands the market. Airgunners don’t want 20-yard minimums – field target drives a 10-yard minimum (and Leapers drops it down to 3, just because they can). Rimfire shooters don’t need 20 yard minimums, and centerfire shooters barely know what parallax adjustment is. A company with scopes set to a minimum parallax distance of 20 yards is a company that’s out of touch with potential buyers of their products. China will make anything you want.

I’m saying that to be a proper airgun scope, the parallax adjustment must go down to not more than 10 yards minimum.

WHERE is the parallax adjustment located?
AO is code for adjustable objective. That’s where the parallax is adjusted. At the SHOT Show, I have met scope “manufacturers” who didn’t know what the letters AO stood for or how it worked. Clearly not airgun scope makers! But better airgun scopes now have the parallax adjustment on the left side of the scope, and REALLY great scope makers also sell giant adjustment wheels for use in field target. Not all of them know WHY field target shooters want those big sidewheels, though, so I now see some scopes that only adjust down to 20 yards being sold with a large sidewheel. That’s the equivalent of trying to sell a Corvette with a trailer hitch and a four-cylinder diesel engine! I think they believe the large sidewheels are a styling element.

Reticles
Another good way to tell if a scope is for airguns is by the reticle. Every day I see more and more fancy and meaningless reticles pop up in the marketplace. The mil-dot is the current rage, and I hate it when someone buys one and then turns to me to explain how it works. I tell them of the military WORM formula used by artillerymen to measure distances on the battlefield, and they come back with something like, “But I want to use it to hunt squirrels!” Sure they do! They also want to use a full-auto Drozd running on air and a car battery to hunt squirrels, because that sounds cool, too. [Don't you DARE ask me for the plans on how to set up that gun!]

If the reticle looks like it belongs in a tank fire control system, it probably does. If the ballistic reticle is adjusted to 400 yards for a 180-grain Silvertip traveling 2,600 f.p.s., don’t expect to magically adapt it to the trajectory of an 8.4-grain JSB Exact going 900. Airgun reticles are made for airguns, and they’re either simple crosshairs, duplex crosshairs or some simple variation on that – like the Gamo scope I showed you last week. If you must have mil-dots, buy them and then experiment to discover what usefulness, if any, they offer you.

Scopes have changed radically in the past 15 years, and breaking them with an airgun is no longer the issue. Look for the proper parallax range and a good reticle. All other features are icing on the cake.

57 thoughts on “What makes an airgun scope?

  1. hi bb
    thanks for answering my glasses- contacts question a few days ago. i was on vacation so i just got to read it today. i have 2 questions
    1: do you know of anyone who makes a drop in replacement trigger for the 392? i did some googleing but i cant find anyone
    2:would enough duct seal stop a 40 grain rimfire bullet?
    thanks
    Nate in Mass



  2. Duct Seal

    Enough ductseal would stop a .357 magnum bullet, but the question is, are you able to put enough on your backdrop…


  3. BB,
    Thanks for explaining the questions that seem to come your way constantly with all the technical questions of scopes.
    Not to steal your thunder, but for the guy who wanted to know what the virtue of the side wheel parallax adjustments is for field target, consider just how much easier and quicker it would be to be able to adjust your parallax correction quickly without having to peak at your objective bell and reach so far forward to turn it.
    Field target shooting would go much more smoothly with the quicker adjustments and shooter fatigue less likely to set in.
    FWIW, it looks as if most of the scopes being marketed at airgunners these days (including the well respected Leapers) come with mil-dot reticles using duplex posts.
    I myself tend to prefer the plain duplex, but at least as long as the dots aren’t intrusive, I can live with them.
    However, I do see some use for them.
    I have discovered that my CFX sighted at 25 yards using my particular scope will strike three dots low at 75 yards using the pellet I sighted it for, four dots low with Kodiaks, and five dots low using Crow Magnums.
    They serve as nice points to assist in correcting elevation that work better for me than the old standard “kentucky windage.”






  4. So BB.

    I’ve got a full-auto Drozd that I’d like to….

    Ow! Ow! Stop hitting me. It hurts!

    Although I am not currently using scopes I find you blogs on them great and interesting. Still waiting for the next installment in the field target saga.

    Rabbitt :-)



  5. BB,

    Have you done any work with Brownell Acraglas Gel? I am thinking of doing my RWS 36 0.22 to see it it improves somewhat. I still average 1″ groups at 50 ft with the best pellet I’ve found – H&N FTT’s Followed by JSB’s 15.8 gr version. I have done a tune wiht the JM GRT kit as well as field lapped the crown. Groups went from liniear verticle strings of 1.5″ to rounder groups of 1″

    I just can’t get it to group better. I blow this gun away with a standard RWS 34 or an HW80 by leagues.

    KTK



  6. BB,

    This is off topic, but I would appreciate your opinion. I’ve read your reports on both, so:

    I can buy a refurbished RWS 52 for about the same price as a new BAM 40.

    Which would you prefer for hunting?


  7. B.B,

    Good info on what makes an airgun scope! I’d like to add that you can’t always believe what the “manufacturer” printed on the packaging either. I was at a major sporting goods retailer the other day and purchased a BSA S4x32WR scope that was labeled on the packaging by BSA as an air rifle scope. Neither the packaging nor the instruction sheet provided any specs, although the instructions referred an awful lot to hunting. A check of the BSA website confirmed my suspicions. It is a rimfire scope with parallax fixed at 50 yards. The scope has been returned. BTW, Pyramyd sells that scope too, but shows what the parallax setting is.


  8. Hello B.B.,
    With the standard 50years+ farsightedness I have, I have to screw the eyepiece adjustment on my scope out to get the cross hairs in focus. No problem. When I focus the AO, the markings on the scopes (2 different Leapers) always show farther (25-75%) than the actual measured distance. As I don’t use the markings for range finding, I don’t really mind. Is the lack of correspondence normal?
    Thanks very much,
    Pestbgone




  9. B.B.,
    OK, now that you say it lke that it makes sense. It’s like handing someone else a pair of binoculars that you have focused on a not to distant object, and then they have to adjust them to get it in focus for their eyes.
    Thanks,
    Pestbgone



  10. Hello,

    I asked the other day about mounting a compact Leapers to my HW30S.

    I’m going with the two piece mount. Do they need to be adjustable for this gun?

    Are there mounts you can recommend?



  11. The HW 30 is the Beeman R7 in a different stock. So recvopil isn’t a big probloem. Neither is scope droop. I think you can get by with a non-adjustable scope mount.

    Use a good two-piece mount. It will have to be 30mm dfot the Leapers 3-12 X 44 scope you have chosen.

    B.B.


  12. Nate asked about a trigger swap for the Benjamin 392, and there is nothing available because the trigger is not unitized.

    Are there directions for tuning those triggers? I’ve looked everywhere on line the past three days and found nothing.

    I really love this blog. After spending the weekend worrying the subject, someone else asked MY question! Thanks, Nate. And, thanks, B.B!

    fflincher


  13. fflincher and Nate.

    The 392 trigger is pretty straightforward, so I don’t know if anyone will take the time to document tuning it.

    But let me make you aware of a danger. The trigger parts are hardened, so if you reshape then you have to make sure they are rehardened or the trigger will be unsafe.

    The parts are made from low-carbon steel, so you will have to case-harden them.

    B.B.


  14. Pestbgone,

    My leapers 3-9X50 is way off for paralax adjustment like yours. If the targets 20 yards away, mine is focused at about 40 yards according to the markings. Too bad you couldn’t callibrate the markings by adjusting the bells position. Maybe you can?

    Kyle.


  15. Kyle, Pestbgone and anyone else,

    Nobody trusts the yardage numbers engraved on the parallax ring because they are only accurate at one temperature setting. When the weather turns cold this fall, you will find them to be closer to correct, and this winter they will be wrong again.

    This is why people put white tape around the parallax ring and write their own numbers on the tape from actual testing. To be really correct, you need at least three scales, each calibrated for a different temperature range.

    B.B.


  16. I’m having a difficult time with the search feature on this blog.

    Maybe I’m crazy, but wasn’t there a blog on the Sam Yang 909S? It was called something like,” Sam Yang 909S hunting airgun.”

    Can anybody send me a link?



  17. Thanks, Nate!

    Shootin’ ice cubes sounds like fun, but I live in south Texas and they don’t last long enough for me to draw a bead, let alone walk back the 110 feet!

    fflincher



  18. I am having trouble with a scope moving in the scope rings. I have looked but I couldn’t see a comment on this problem.

    It appears that the scope has shifted backward in the rings steadily since I mounted it. It appeared tight when I mounted it, and I am going to have to loosen them to shift the scope forward.

    How can I do this so that it doesn’t shift again, and how can I level it so it’s straight? Also I’m concerned that I kept adjusting the scope to keep it on target and I may have over adjusted it? How would I know and how can I set the scope back to zero point for windage and elevation, so I can resight it in?

    Oh, I am using a Remington Genesis 1000x with the scope that came with the combo.

    Thanks in advance,
    BoB



  19. BB thanks for the quick reply. The rings were pre-attached to the scope but the scope I mounted on the gun. The scope is moving in the rings, not on the rifle.

    The rings torque down with 4 screws.

    Also does the elevation and windage adjustments on the scope have a hard stop, or do they just keep going around and around and feel different, of which I would not be familiar?

    Seperately the Genesis has started to develop a rattle after it is fired. I have fired only about 75 to 100 shots through it, is this something you experianced when testing it? (the grinding, during cocking, has stopped like it did in your test)

    Thanks again for the info, and great Blog – needless to say very informative.

    BoB


  20. Bob,

    I think you need to remount the scope and tighten the ring cap screws properly this time.

    Some scopes have a hard stop on the adjustment knobs, but there is a release that allws you to turn the knob another rotation. Other scopes have no stop.

    Those without a stop get looser as they approach the end of adjustability in one direction (usually up or to the right) and tighter when they reach the end of their adjustment in the other direction.

    The Genesis rattle is the powerplant loosening up, I think. As long as performance remains the same it should be nothing to worry about. But a good tuneup would quiet it considerably, which you would probably like.

    B.B.


  21. I had an interesting experience while sighting in a scope and would like to hear your thoughts. I was at my father house last week and we were sighting in the airgun scope on his very old RWS Diana break-barrel spring piston rifle (the scope isn’t very old). At a distance of about 15 yards we were both shooting 3shot groups that covered a quarter, but my groups were about 3 inches higher than his groups. We were shooting off a bench with a rolled towel supporting the front of the stock (no part of barrel or hinge touching) and the rear of the stock resting on the wooden bench. I did notice that you can change the point of impact by about one inch if you look through the scope slightly off center, but this is very noticeable during normal shooting because the view starts to black out because you’re not in the sweet spot of the scope anymore. Can you explain why there can be such a difference in height of the groups? Is it because he’s 74 years old and I’m 43?


  22. Two words – parallax and hold. With the artillery hold your groups would both have printed in the same place, as long as your eyes were in the same place.

    Parallax will move a group a small distance at 15 yards. Hold will move it a lot.

    B.B.


  23. A comment on scopes. I made it to the local range yesterday after several months of being too busy at work. I own two rifles that are well known scope breakers. A Webley & Scott Patriot in .25 and a RWS 350 Magnum in .177. I hunt with both rifles shooting exclusively heavy pellets. I purchased identical Bushnell Banner 4x12x40 AO scopes for each of the guns because I liked the optics, and the price was right. Bushnell recommends these scopes for air rifles on their website. The reason for the trip was to sight in the 350M for the first time with this scope. After about 75 rounds I noticed my groups moving unexpectely by 3 to 5 inches on the target at 50 yards. I would adjust the scope to center only to have it move in a new direction. I was beginning to suspect that the scope was defective when I noticed an o-ring that was half out of it’s groove on the rear lens. The glass was loose and would cock to the side blurring the image. I set the 350M aside and grabbed the Patriot. Looking at the rear lens, I noticed that it too had come loose and the o-ring was nowhere to be found. I have probably fired this rifle 450 times with the scope attached. Dispite having the loose lens, the Patriot still groups in about 1.5″ at 50 yards. Both these scopes were purchased at the same time and came from the same lot/shipment. I have shipped them back to Bushnell for warranty service but given that they both failed in the same way, I’m not confident that this scope, even when repaired will last on these rifles. Has anyone else had similar problems with the Bushnell Banner scopes on a springer? It seems that they really need to address the engineering of the optics if they are going to market these as an air rifle scope. The worst part of it all is that both guns are out of commission at the same time. If there is a similar scope that I could trust not to fail, I’d sell these two on eBay when I get them back and purchase another brand/model. Any recommendations would be appreciated.


  24. I’m sorry to tell you that Bushnell Banner scopes have this reputation. They are among the least expensive of the Bushnell line, and the more powerful springers will wreck them.

    Bushnell makes some fine airgun scopes, starting with the Trophy line and moving up from there, but the Banner scopes shouldn’t be used on magnum spring guns. They are fine on the lower-powered springers and on non-recoilling airguns

    This is the reason I always recommend Leapers scopes. I know they are rugged enough to take the punishment of the harshest spring guns, despite the low price.

    B.B.


  25. B.B.

    When a 4-16 scope is said ta have 10 yards minimum AO focus, is that only for the minimum power?

    What minimum distances can I expect for the other powers?

    Thanks a lot



  26. B.B.
    I found a fairly inexpensive Bushnell scope at the local Academy Sporting Goods and although it’s not labled for air gun use it was labled “Shock Proof”. I read on the back of the package where it was made in China but for all I know they could all be made there. Everything else is… Anyway, do you think this or any scope labled “Shock Proof” will hold up on an air rifle?

    As usual, thanks a million.

    Bill S.


  27. Bill S.,

    I can’t say whether your new scope can hold up to an airgun, but Academy should stand behind it if it doesn’t. Most scopes made these days are built to take magnum spring airgun recoil and vibration. Only some of the cheaper Chinese models like Red Star are still not there.

    B.B.


  28. I love shooting air rifles and .22LR. I use 3-9x32AO mildot on the LR and simple 4x32AO mildot on the air rifles. All Leapers with finger ajd. turrets. Shooting subs and high velocity .22LR it’s nice to have flexabilty in the scope.

    I do have some left over scopes that came with my air rifles: 4×32 px fixed at 20 yards. From Powerline to crosman to centerline etc…

    Some i’m selling and set the px for .22LR and some for 10M air rifles etc….

    To set the px on a the fixed scopes I loosened the ring on the objective lense and moved the double threaded ring that hold my objective lense. Inward to lower the px and out ward to raise it. I measure out the distances then turn to focus in to set.

    As for mil-dot reticles I never got into the TRE formulas etc…I just use as a basic guide and sometimes holder over under and windage points.

    AO may not always pinpoint your range, but it does help you get close enough to be effective and greatly helps to paint your target when you don’t have a lot of time.



  29. This tip was from the reviewcentre.com shooting forum from two stage who posted a linked from airgunforum.net about a post by 1to5.

    I’m flattered by your request, but my writing skills are very poor. Perhaps if you have the time to check it out, that would probably be better.

    I just mainly like to share ideas. I try to keep of list of tips that have helped me. At least half of them are from you. LOL!!!!

    Luckily, we have the internet. Without the internet, it would probably be much harder to find information on airguns and the supplies we need for them.

    Like my good friend always say, “you can never go wrong when talking to another airgun shooter, they always tend to be good people.”



  30. Zel,

    Just for the record, I used a scope for centerfire rifles on an FWB 124 for several years without a problem. So the fixed parallax isn’t as great a problem as it sounds.

    My pick would be the Tactedge 4X40 long eye relief scope for the 61. You don’t need the eye relief, but it’s a wonderful scope in all other aspects.

    http://www.pyramydair.com/cgi-bin/accessory.pl?accessory_id=1683

    It’s $13 over your budget, but it’s worth it.

    Other than that, any scope under $40 whose features you like. I haven’t tested any of them so I really don’t have any experience.

    B.B.



  31. Zel,

    The fiction of “see-through” rings is just that. The rings have holes for lightening the extrusion from which they are cut. A marketing department called them see-through. I doubt you will be able to use them that way.

    I like the medium rings best, but I am able to fit many rifles easily. High rings will give you more latitude.

    B.B.


  32. hi B.B.

    I have seen the Leapers 3-9x32mm Range Estimating A.O. Full Size Scope:

    http://www.pyramydair.com/cgi-bin/accessory.pl?accessory_id=866

    It’s a little more small than the tactedge, and have zoom and adjustable objetive, maybe i dont need these features, but i want to learn how to use them. What do you think about this scope?

    Seem they don’t include the rings, so what rings are a better fit to a izh-61?

    Maybe these are good? :
    http://www.pyramydair.com/cgi-bin/accessory.pl?accessory_id=793






  33. i have find this faq:

    http://cz452.com/cz452-faq.html

    here explain the differences beetween the 3/8 and 11 mm,
    and that maybe in some cases it will work:

    “Some 3/8″ rings will work with the 11mm dovetail. It depends on their design as to how well they work.”

    so i think is safer to use 11 mm rings and not use 3/8 rings.

    But i want to use medium heighs rings and the only 11 mm ring i can find is high profile:

    http://www.pyramydair.com/cgi-bin/accessory.pl?accessory_id=635

    so i dont know what to do, use the high profile rings or try these medium heigh 3/8 rings:

    http://www.pyramydair.com/cgi-bin/accessory.pl?accessory_id=793

    and hope it will work?

    Thanks a lot.


  34. Zel,

    3/8 and 11mm are often interchangeable. Leapers believes that .22 rimfire buyers outnumber airgun buyers, so they label their mounts 3/8. They all fit 11mm grooves.

    If you are looking at another brand, I advise caution.

    B.B.


  35. Zel,

    3/8 and 11mm are often interchangeable. Leapers believes that .22 rimfire buyers outnumber airgun buyers, so they label their mounts 3/8. They all fit 11mm grooves.

    If you are looking at another brand, I advise caution.

    B.B.


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